I had bought a filtermag few months ago(yeah I know gimmick) but just did my second oil change on the d using this thing and I had noticed that the oil looked like i just put it in no more sludge etc. i decided to cut the filter open. to my surprise the paper element was completly clean but where the filter mag was on the filter you could see the crap stuck to the outside wall of the oil filter. never in my time as a wrench have i seen clear oil come from a motor with 130k on it and i didn't do any flush just changed the oil installed a new filter with the filtermag on the outside of the filter. I have had this on for 6k and I am fully satisfied with these results.

 

what is a filter mag??

 

it's a magnet that slips over the oil filter. supposed to be good at catching particals down to the 2 micron level. Havent used one but would consider it if I didnt already have a bypass filter setup on my CTD...